<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="./css/normalize.css">
    <link rel="stylesheet" href="./css/bootstrap.min.css">
</head>
<body>
    <!-- 
        text-danger  字体颜色
        bg-danger  背景颜色
        danger 在table中使用，作用于tr里面的td
        bg-danger  在table中使用，作用于tr
     -->
    <h1 class="text-danger">h1</h1>
    <h1 class="bg-danger">h1</h1>
    <a href="#" class="btn btn-danger">按钮</a>
    <table class="table table-bordered table-striped table-hover">
        <thead>
            <tr>
                <th>列1</th>
                <th>列2</th>
                <th>列3</th>
            </tr>
        </thead>
        <tbody>
            <tr class="danger">
                <td>列1</td>
                <td>列2</td>
                <td>列3</td>
            </tr>
            <tr class="bg-danger">
                <td>列1</td>
                <td>列2</td>
                <td>列3</td>
            </tr>
            <tr>
                <td>列1</td>
                <td>列2</td>
                <td>列3</td>
            </tr>
        </tbody>
    </table>
</body>
</html>